En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?


Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
3 ratings

Saturday - February 09, 2008

From: Portland, OR
Region: Northwest
Topic: Herbs/Forbs
Title: Rubber (latex) in Balloon plant (Asclepias physocarpa)
Answered by: Nan Hampton


I need milkweed leaves that contain rubber. The common milkweed species Asclepias syriaca has rubber in it. Do the milkweed of Balloon plant milkweed (Asclepias physocarpa) contain rubber?


Asclepias physocarpa is a native of southeast Africa and our focus and expertise is on natives of North America so this plant is not really in our purview. However, we can answer your question. The majority, if not all, of the milkweeds—in particular, the members of the Genus Asclepias, including A. physocarpa—contain the sticky white latex sap that you see when you cut or break the leaves or stems. The latex, plus other chemical components such as cardenolides, are the plants defense against herbivores. There are insects that do thrive on the milkweeds (e.g, the monarch butterfly, Danaus plexippus) and have devised strategies to subvert the plants's defenses. You can read more about the plants defense strategies in: Angrawal, A. and M. Fishbein. 2006. Plant Defense Syndromes. Ecology 87(7) Supplement. S132-S149.


More Herbs/Forbs Questions

Grapeland, TX is NOT Grapevine, TX
July 25, 2013 - I submitted a question and today received my answer. I do thank you for this valuable service. However, I stated that I lived in East Texas in GRAPELAND, Tx. Nan Hampton answered me and said that a...
view the full question and answer

Mulching Spring Bulbs in Upstate NY
October 25, 2010 - Just planted tulip bulbs for Spring. The Parks Department then put 4 inches of mulch on top. Will the tulips be able to get through and bloom come Spring? Is mulch a good winterizer for them? Indoor c...
view the full question and answer

Flowers under pine trees from Elkhart Indiana
May 02, 2013 - I have a number of pine trees at the back of my lot and would like to plant flowers under the tree. What can I plant?
view the full question and answer

Planting horsetail indoors from Collierville TN
November 12, 2012 - I would like to plant horsetail indoors. Can it handle the inside? Will it try to go dormant or it that a temperature trigger which means it will not go dormant?
view the full question and answer

Plants to prevent erosion in IL
August 02, 2012 - We just got done building a house and have leveled all of the dirt piles. We do have a row of straw bales to help prevent the dirt from washing onto the neighbors property. It is the wrong time of ye...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center